\n<\/p>\n
An artist\u2019s impression of what asteroid 2024 YR4 could look like as it approaches Earth in December 2032<\/p>\n
NASA<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
NASA has upgraded the risk of asteroid 2024 YR4 hitting Earth in 2032 to 2.6 per cent, or 1-in-38, the highest odds yet of collision.<\/p>\n
Astronomers discovered that the asteroid was barrelling towards Earth in December and it has been a focus of the world\u2019s telescopes and space agencies ever since. As they gather more data on the precise orbit of the asteroid, astronomers have been able to calculate how likely it is to hit Earth with greater precision. The asteroid is thought to be between 40 and 90 metres wide and has the potential to release energy equivalent to 7.7 megatonnes of TNT should it hit Earth \u2013 enough to destroy a city.<\/p>\n
According to NASA, the odds of collision in 2032 have been edging up from 1-in-83 since it was first spotted, to 1-in-67, to 1-in-53, 1-in-43 and now 1-in-38. The European Space Agency gives slightly different odds, currently giving a 2.41 per cent of collision.<\/p>\n
This steady increase does not necessarily mean that the asteroid is actually more likely to hit Earth, however, and the odds may yet come down. \u201cJust because it\u2019s gone up in the last week, doesn\u2019t mean that it\u2019s going to continue to do that,\u201d says Hugh Lewis at the University of Southampton, UK.<\/p>\n
<\/p>\n But we are running out of time to forecast the risk. One issue is that 2024 YR4 will fly behind the sun in April, placing out of view of most Earth-based telescopes. That places a limit on how much astronomers can refine their predictions, says Lewis. \u201cAny observations we can make between now and when it\u2019s out of view will obviously help us to refine the orbit and to make better predictions. That doesn\u2019t necessarily mean that it will go down before April. It could continue to go up, but still ultimately miss us.\u201d<\/p>\n Once the asteroid does fly out of view, it will be unlikely that we will gain any more information before it comes into view again in 2028. However, astronomers could comb through past data to uncover previously overlooked observations of the asteroid, which would help refine its trajectory. That process is already being undertaken by the world\u2019s space agencies, says Lewis.<\/p>\n Crucial information on the size and composition of the asteroid will hopefully be gathered by the James Webb Space Telescope in the coming months, says Lewis. This will help us understand whether the asteroid could make it through Earth\u2019s atmosphere intact and how large an explosion it could cause if it does impact Earth.<\/p>\n \u201cThat will help us determine what we need to do about it, because if it\u2019s a stony asteroid, that\u2019s very different from a high proportion of iron-metal asteroid,\u201d says Lewis. An iron-rich asteroid would be worse, as a stony asteroid would potentially break up during impact. \u201cThe mass makes a huge difference in terms of the energy and whether or not the atmosphere has an effect on it.\u201d<\/p>\n Topics:<\/p>\n<\/section><\/div>\n